1. Field of the Invention
The present invention relates to a two-piece sheet metal nail assembly and in particular relates to a two-piece sheet metal nail comprising a one-piece stamped shank portion adapted to be driven into and retained in a structure and a one-piece stamped head portion adapted to be quickly and easily assembled to the shank portion.
2. Description of the Prior Art
Sheet metal nails for securing panels or the like to a support structure are well-known in the prior art. In particular, such sheet metal nails are well known for attaching slabs of insulation or the like to metallic roof decks or the like.
One type of prior art sheet metal nail is a one-piece structure utilizing an integral head and shank portion. Such nails are extremely desirable for many applications wherein the required surface area of the head portion and/or the axial length of the shank portion did not exceed certain limits. Examples of such nails may be seen by reference to U.S. Pat. No. 3,710,672, issued Jan. 16, 1973, and U.S. Pat. No. 3,983,779, issued Oct. 5, 1976. However, when a greater axial length of shank portion or a greater surface area of head portion was required, such one-piece nails were not totally satisfactory as extremely large capacity stamping presses were required to produce same, the stamping procedures to produce same were unduly difficult, and/or expensive, and/or the nails were not easily and/or compactly shipped.
The prior art has also included multiple-piece sheet metal nails which were useful when an especially large axial length of shank portion and/or surface area of head portion was required. An example of such a multiple-piece nail may be seen by reference to U.S. Pat. No. 3,088,361, issued May 7, 1963. The prior art multiple-piece nails were not totally satisfactory as they required preassembly as by a welding or fabrication operation, they required an unduly large shipping container, they were difficult to properly assemble in the work place, and/or required specialized assembly tools.